Variable speed drive



March 24, 1936. o. 1. JUDELSHON VARIABLE SPEED-DRIVE Filed June 28', 1955 ATTORNEY Patented Mar. 24, 1936 UNITED STATES PATENroF ICET r- VARIABLE SPEED muvrf: Oscar I. Judelshon, Park Ridge; J. Application Jlme 2a, 1935, steam. 28,796

10 Claims; (c1; "ii-230.17)

My invention relates to thetype of variable speed drive or transmission which includes an endless member or belt which travels over a pulley, the flanges of which are relativelymovable toward and from each other in order] to vary the radius of the are which the belt travels around the pulley to vary the speed ratio between the driving anddriven members. In my co-pending application Serial No. 27,918 I have shown and described a variable speed drive'having manyof the characteristics of the present invention, ,but in that case I showed my invention embodied in a construction in which springs were employed to move the flanges of the expansible pulleys, although the cIaimsin'that application are not necessarily limited to a construction employing the springs. The general purposes of the present invention are similar to those of the invention disclosed in my said co-pending application-but the present case discloses a-construction wherein the springs may be eliminated and positive means erable space; means required considerable force or it requiredconsiderable time to make the adjustment. The

may be employed for varying the flanges of the expansible pulleys to control changes in the speed ratio between the driving and drivenmembers.

In one of the variable speed drives of the'belt and pulley type now on the market an endless belt travels over two pulleys, each havinga pair of flanges, the flanges of each pair being adjustable toward and from each other by meansof a lever system, so that one pulley is in effect made smaller and vice versa, and by this method the speed ratio as between a driving and driven member is varied asdesired.

The belt is of the v type to fit between the flanges of the pulleys as these have slanting or frusto conical opposed faces. While this former type 0f drive or transmission wide range of speed changes, the construction of the apparatus was expensive; it required considand the operation of the adjusting present invention forms a complete displacement of the former drive just described. I

The drive or transmission containing my present invention is much less expensive to make for any particular dutyto be performed; it is more compact and therefore it occupies'less space, and it is adapted for attachment to all kinds of machinery and in various positions. The device permits of the widest speed variations, the operation of the speed change member requires but slight force, and there is a minimum of vibration and complete lack of noise during change from one speed to another. So little force is required provided a very to vary the speed ratio between the driving and driven members that thepresentdevice may be :coupled. with some machine which is driven by the device to make thespeed change automatically with the requirements'of the machine, thereby making-the present drive applicable to many kinds of machines where former variablefdriv'es were not applicable.

The present drive maybe employed for operating lathes,drill presses, shapei's and planets,

as well as innumerable other machines. because of the characteristics pointed out above, and also because thepresent drive is so inexpensive that when applied to the machines its cost will not be disproportionate with the total cost of the equipment. It may replacethe ordinary stepped pulley drive in such machines. Where thepresentinvention is used in its complete aspect,twoex'pansible pulleys are formed side by side,and including a pair ofouter flanges with a shiftable inter- L mediate flange which-is common to both pulleys.

Change in speed is effected by changing the position of the expansible pulleysand'by simultaneously shiftingthe twoouter flanges which causes an automatic shift of the intermediate 01-1 common flange. In the present case I show posi -tive means for shiftingthe outer flanges of" the expansible pulleys for changing the effective sizes of the expansible pulleys in order to change the speed ratio of the, drive. s I

Other advantages will be set forth in the following detailed-description of my invention.

tion, i

Figure 1 is a plan view of a variabledriveembodying my invention,

in the opposite-position to that in Figure 3,

a grooved pulley 2, fixed on the shaft of the motor.

The driven member is shown as a grooved pulley 3 mounted on a shaft 4 fromwhich the power is taken for operatingany. kind of machine or ap- I paratus requiring a variable drive. The..motor is shown as mounted on a base 5 and the brackets, 6

In the drawing formingpart of this applicadrivewith parts broken away andlshowing the The inter-medi I upwardly I the ,flangemember 2 ior supporting the shaft 1 in spaced relation to the motor are also shown as mounted on this Between the motor and the shait l I have shown mounted on the base a pair of spaced brackets l in which is iournaled the shaft 1 which is adapted to shift axially in its bearings. On this shait mixed the u extending and spaced lever arms 8 inwhich is iournaled the shaft I which I and with the shaitl. On the shaft] are mounted members constituting the two xpansible pulleys A and B.

The pulley A consistsin part The pulley 3 consists in part oi the'flan ge memher i2 which is fixed to the shaft aslbya pin is 3.3883121113011811. the hub oi the iiange member and he t.

inserted in a member, the key being turned end is which is secured against one end oi by a screw l1. This'key engages in the keyway I. ic'rmed in the shaft 1.

The flange member It has a irusto conical iace cooperating therewith to iorma grooved pulley.

te flange member also has conical iace 22 iacing toward the 'irusto conical iace 20 oi the flange member and co-operating .therewith toiorm the grooved pulley B.

I have shown one oi the lever arms 8 extended to iorm a lever arm 23 having an operating handle 24 at its other end. There is a sliding member 25 secured in suitable bearings on the lever member 2% arm s. and the and the lever lower end oi this slidin member is turned at an angle as shown at 26 and is adapted to co-operate with the teeth oi an arcuate rack 21 'iormed on the upp edEe' oi one ofthe brackets 6 ior the purpose oi locking the lever arm 23 in various adjusted positions.

There is an endless belt 2l-oi the V type engaging around the driving member 2 and around the pulley A, through which belt the operating iorce is taken irom the driving member 2 to operate the shaft 9 on which the espansible pulleys are mounted. One loop oi this belt has its edges engaging between irusto conical surfaces is and 2! of one oi the side flange m bers and the intermediate flan e member.

There is another endless belt 29 oi the V type which travels around the pulley B with its slanting mediate flange member. around the gr 7 ed pulley which power may be taken to operate any type oi machine or apparatus. I have provided means ior shiiting axially co-incident with the swinging oi this shait into diilerent positions by the swinging motion oi 8. f For this purpose I have shown a gro ve Ii extending at an axis oi the shaft 1 this cam being the shaft 1 to oscillate therewith as shifted axially with the lever arms traction ior illustrated intermediate upon the locking inclined side,

- place.

0 operative action oi the cam the shaft 8 by means oi a set screw 82. There is an arm a secured to one oi the brackets s and on the iree end oi this arm there is a stud an antiiriction roller 25 whlch .travels in the groove 3| oi thecam.

operation In the operation oi the present invention it is possible to retain both belts 2|, 2! in straight lines or in other words the middle lines oi these belts do not shift duringchanges oi the speed ratio oi the drive. This makes it possible to employ a grooved pulley ior the driving member and a grooved pulley ior the driven member to obtain maximum driving heavy loads.

when the parts are in the position shown in 34 which carries 7 Figure 3 the driven member I is operated at minipeed because at such time the dense memthe intermediate flange member a close together and the belt 2| is traversing a relatively large are around the pulley at a lower rtions because the driving pulley issmaller thanthe eiiective size oi'the pulley A it results in a reduction oi speed as betwen the'driving pulley 2 and the pulley A; At this time the leit flange member I2 is relatively'iar irom the cooperating iace oi the in the drawing,

29 is traversing a relatively small are around the pulley B.

In the propo time the eiiective size I than the driven pulley 8 and therefore there is a iurther reduction in speed as between the shait t l. During the condition shownin Figure 3 the lever arm 23 is thrown in a clockwise direction to a position where the locking member 26 engages-the slot furthest to the left in the archate segment 21. In other words, this time is nearest the dr ving pulley and iarther iromthe driven pulley. At such time also, shaft 1, is in its farthest left hand position as shaft 0 and ons shown in thedrawing, at oi the pulley B is smaller shown in Figure 3 and therefore the in their extreme left hand position.

Letlt be assumed that the parts areto be shifted into a position which will increase the speed ratio between the driving and driven 'members. v'lio do'this the locking member 26 is" released from the sector 21 and is moved clockwise as viewed in Figure 2, where member is allowed tovreengage the sector 21 to lock the parts in theadjusted position. i While the lever arm 23 is thus being rocked clockwise in Figure 2, the iollowing actions take The shaft 1 is moved with the lever arms 8 and the shait l andthis moves the shait .irom its position nearest the driving pulley and to a point nearer the driven pulley. At the same time the shaft 1 isshiited axially by the coand the stationarily mounted roller 35 irom the leit hand position in Figure} to the rightv hand position show! and alters the distance between this mem berand the two end ilanse members. This causi the eiiective size of the pulley A to be reduce so that the arc travelled by the belt 2| arour thepulley AisreducedasshowninFigm'eLar expansible flange member i4 so th'at the belt the lever arm 28 the shaft'l'at I the of the pulley must take place while the belts are running The intermediate flange member I4 is not directly shifted by the axial movement of theshaft 9 but indirectly through the change of the arcs of the belts.

In other words, the position of this intermediate member is changed by theaction of the belts in co-operation with the two end flange members, The distance between the end flange members does not changebut theirposition is shifted with the shifting of the shaft 9. a

When the parts are in the position shown. in Figure 4 the effective size of the pulley A will have been decreased because the end flange member l and the intermediate flange member M are spaced relatively far-apartso that the loop of the belt 28 travelling around the pulley A is a relatively small arc and the driving member will therefore operate through the pulley A and belt 28 to drive the shaft 9 at a relatively high speed. on the other hand, the flange member 12 and the intermediate flange member ll are at this time relatively close to each other so that the belt 29 travels in a relatively largearc around the pulley B so that there is a further increase of speed as between the shaft 9 and the driven pulley 3.

From what has been said,it will be apparent that as the effective size of the pulley A grows smaller the effective size of the pulley B grows larger in direct accordance with the movement of the shaft 9 in relation tothe driving and driven members. The speed ratio between the driving pulley and the'driven pulleywill be at maximum when the parts are in the position shown in Figure 4. As between the condition shown in Figures 3 and 4 there may be any variation in the ratio as between the driving and driven members, depending upon the positionof the lever 23. By positively moving the flange members l0,

. l2 at the same time that the shaft 9 is-shifted by the rocking of the arms 8 I am enabled to use positive'means for shifting the flangesof the expansible pulleys and to eliminate the use of springs which are shown in my co-pending application. In many cases it is preferable to avoid them of the springs, whereas in other instances the springs may be desirable.

It will be obvious that it is not, necessary to shift the shaft 9 at right angles to its axis on swinging arms as direct reciprocating motion may be employed, although the swinging armsprovide very simple construction. It is not necessary to employ a particular type of cam for shifting the shaft 8 axially but it is desirable, if not absolutely necessary, that the shaft 9 be shifted axially at the same time and in synchronism with the shifting of the shaft. .9 in relation to the driving and driven members.

If the belts, through wear or stretch, become slack, the motor i may bershifted on its base in accordance with common practice and this will simultaneously tighten both belts 28 and 29.

Having described my invention, what I claim is:

1. In a device of the character described, a driving pulley, a driven pulley, a plurality of endless belts of the V type travelling respectively around said driving and driven pulleys, a shaft,

flange member common to both expansible a plurality of expansible pulleys of the V type on said shaft, including end flange members and an intermediate flange member oommon'to both expansible pulleys, means for. fixing thedistance between said end flange memberasaid interme-. diate flange member floating-between the end flange members, and means foraxially shifting said end flange members. to vary. the j effective sizes of said expansiblepulleys'in reverse order, said belts travelling respectively around saidex-J l pansible pulleys.

2. In a device 'of driving pulle .a driven pulley, .'a plurality of endless belts of theV typetravellingrespectively around saiddriving and 'driven'pulleys, a sh'aft, 1 a plurality of expansible pulleys of the .V type on i th nd d s ibed; a

said shaft, including end flange members flxed to saidshaft at,.,-a flxed distance; apart to revolve therewith, and an intermediateflange member common to both expansible pulleys,"said intermediate flange member connected to. revolve with said shaft but slidable alongfthe. same'to float between the end fl nge members, and means for axially shifting said end flangev membersto vary the effective sizes of, said expansible pulleys v in reverse order, said beltstra'velling respectively around said expansible pulleys". P

3. In a; device of, the character described'a driving pulley, a driven pulley...aplurality of endless beltsof the v, type travelling" respectively 3 around said driving and driven pulleys, a shaft,

a plurality of expansible pulleys of the 'V type:

on said shaft, including end'flange members fixed to said shaft at a flxed distance from each other to revolve therewith, and an intermediate flange 3 member common to bothexpansible pulleys, said intermediate flangemember connected to revolve with said shaft and slidable alongthe same to float between said end'fflange members, means for axially shifting said shaft and with its'aid end flange members, to vary the effective sizes of said expansible pulleysjin reverse order, said belts travelling respectively around said expansiblepullys.

4.11; a device of the character'described, a driving pulley,fia driven *pulley,fa plurality of" endless belts of the V type travelling respectively i around said driving and driven pulleys, a shaft,

a plurality of expansible pulleys of the V type on said shaft, including end flange members and an intermediate flange member common to both expansible pulleys, means for flxing the distance between said. end flange members, said intermediate flange member floating between the end flange members but revolving with said shaft, means for axially shifting said end flange members to vary the effective sizes of said expansible pulleys in reverse order, said belts traveling respectively around said expansible pulleys, and

means for shifting. said shaft at an angle to its 6 axis for the purpose described.

5. In a'device of the character described, a driving pulley, a driven pulley, a plurality of endless belts of the v type travelling respectively around said driving and driven pulleys, a shaft, 6 a plurality of expansible pulleys of the V type on said shaft, including end flange members flxed to said shaft to revolve'therewith, and flxed: in spaced relation to each other, and an intermediate pulleys, said intermediate flange member connected with and revolvable with said shaft, and e v slidable along the same to float between said end flange members, means for axially shifting said shaft, said belts travelling respectively around said pansible pulleys, said intermediate flange member the connected to revolve with said shaft but'alidable same to float'between the end flange members, means for axially shifting said shaft to vary the elective" of said expansible pulleys in reverseorder. said belts travelling respectively, around said expansible pulleys, and meansfor shifting said shaftv at an angle to its axis simultaneously with the axial shifting of said shaft. 1

'7. In a device of theeharacter'deacribed, a driving pulley, a driven} pulley, a plurality of endless belts of the V type travelling respectively around said driving and driven pulleys, ashaft, a plurality ofiexll l l ble pulleys of the V type on said shaft, including end flange members flxed to said shaft to revolve therewith, and'an intermediateflange member connected to revolve with said shaft but= slidable along the same to float between the 'end flange members, means for axially shifting said shaft to Va the eifective sizes of said expansible pulleys in reverse order, said belts travelling respe tively around said expansible pulleys, and means for shifting said shaft at an angle to its axis simultaneously and in synchronism with the axial shifting of said shaft.

8. In a device of the character described, a driving pulley, a driven pulley, a plurality of endless belts of the V tlype travelling respectively around said driving and driven pulleys, a shaft, a plurality of expansible pulleys of the V type on said shaft, including end flange members and an intermediate flange member common to both expansible pulleysvconnec'ted to revolve" with, said shaft but slidablealo'ng the same to float between the end flange members. means for axially shiftflange member common to both e xing said flange members to vary'the eifective of said expansible pulleysin reverse order and means for locking said shifting means in various adjusted positions, saidbelts travelling respectively around said expansible pulleys.

9; In a'device of the character described, a,

said shaft and means for axially shifting said shaft simultaneously therewith to vary the effective sizes of said expansible pulleys in reverse order. I v

10. In a device of the character described. a

driving pulley, a driven pulley, a plurality of endless belts o! the 'V type travelling respectively 7 around saiddriving and driven pulleys, a shaft having a cam and means co-operating therewith to shift said shaft axially when the same is cawith saidshaft, and an inter-.

cillated, rocking supports carried by said shaft. 1

a second shaft mounted on said rockingsupports to be moved in relation to said driving and driven members, a plurality of expansible pulleys of the V type on said second shaft including end flange members fixed to the shaft, and an intermediate flange member common to,- both. expansible pulleys and connected to revolve with said shaft but slidable along the same to that between the end flange members, and means for rocking said flrst shaft to vary the spacing of said second shaft in relation to the driving and driven pulleys. and to shift said second shaft axially to vary the eflective sizes of said expansibleipulleys in reverse order. said belts travelling respectively around;

said expansible pulleys. I

I OSCAR I. JUDELSHON. 

